khard: update to 0.18.0.

v0.18.0: 2022-12-10
- Move project home on GitHub from @scheibler to @lucc
- Catch exceptions when loading the config (#294)
- Split $EDITOR env variable on spaces (#314)
- Add special phone number field query
- Add-email command improved: Attach email address to an existing contact
- Add-email command: new option --skip-already-added
- Add partial support for KIND: search query, display in details and listing (#309)
- Add show_kinds config option (#309)
- Add nix flake
- Remove support for python 3.6
- Remove deprecated subcommands "export" and "source"
- Switch from Travis to GitHub CI

(wiz)